So I harvested 3.5 oz of wet hops. Let em sit out in the sun all day and now they are quite dry and weigh only .6 oz. How do I know if they are too dry/not dry enough? Is there a way to calculate the residual moisture based off of weight?
Calculating residual moisture
- Thread starter guldalian
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Also from what I have read, it is commonly reccomended to remove roughly 80% of mosture.
Someone please correct me if I am wrong, but this is my understanding.
When hops are picked, they are around 80% moisture content...which means 80% water, 20% dry matter. The purpose of drying is to get that to 10% or so.
The basic equation for determining moisture content of anything (hops, hay, herbs, etc.) is:
M% = ((Ww ‐ Wd)/ Ww) x 100
M% = moisture content(%)
Ww = wet weight of the sample
Wd = weight of the sample after drying
If you want to know the moisture content, take a small sample and weigh it to get Wet Weight (Ww). Then get the moisture out. Either bake it or put it in a microwave to pull out the moisture. When you are sure it is completely dry, that is your Dry Weight (Wd). Now plug it in to see your starting moisture content.
I wouldn't use that Dry Weight sample in your beer, though. They are extremely dry, crumbly, the lupulinic resins have changed and you will probably burn them the first few times you try.
The problem for the homegrower is that you would need most of your crop to get an accurate enough reading of the moisture content...nearly a 1/3 of a gallon of hops if you have a balance that goes to 2 decimal places when using grams. So it is somewhat pointless.
Instead, let's assume the starting moisture content is 80%. (I have seen from 93% when picked in the rain down to 74% for some smaller cones. So 80% is pretty much the middle.).
Let's pretend we have a 1/2 of a pound of cascade that we picked out of the backyard. Since we are assuming that it starts at 80%, we can use the above formula to calculate the Dry Weight....0.1 pounds.
Now let's say we want to dry down to a final moisture content of 10%. (Commercially, we shoot for 8%, but 10% is fine since you aren't pelletizing.) with a moisture content of 10% and a Dry Weight of 0.1 pounds, the "Wet Weight", which in this case is the weight of the dried hops, would be 0.111 pounds.
Working that out, the ratio of beginning to end weight is 0.111/0.5 = .222 or another way to say it is that the final weight of the hops is somewhere between 1/4 and 1/5 the starting weight.
The basic equation for determining moisture content of anything (hops, hay, herbs, etc.) is:
M% = ((Ww ‐ Wd)/ Ww) x 100
M% = moisture content(%)
Ww = wet weight of the sample
Wd = weight of the sample after drying
If you want to know the moisture content, take a small sample and weigh it to get Wet Weight (Ww). Then get the moisture out. Either bake it or put it in a microwave to pull out the moisture. When you are sure it is completely dry, that is your Dry Weight (Wd). Now plug it in to see your starting moisture content.
I wouldn't use that Dry Weight sample in your beer, though. They are extremely dry, crumbly, the lupulinic resins have changed and you will probably burn them the first few times you try.
The problem for the homegrower is that you would need most of your crop to get an accurate enough reading of the moisture content...nearly a 1/3 of a gallon of hops if you have a balance that goes to 2 decimal places when using grams. So it is somewhat pointless.
Instead, let's assume the starting moisture content is 80%. (I have seen from 93% when picked in the rain down to 74% for some smaller cones. So 80% is pretty much the middle.).
Let's pretend we have a 1/2 of a pound of cascade that we picked out of the backyard. Since we are assuming that it starts at 80%, we can use the above formula to calculate the Dry Weight....0.1 pounds.
Now let's say we want to dry down to a final moisture content of 10%. (Commercially, we shoot for 8%, but 10% is fine since you aren't pelletizing.) with a moisture content of 10% and a Dry Weight of 0.1 pounds, the "Wet Weight", which in this case is the weight of the dried hops, would be 0.111 pounds.
Working that out, the ratio of beginning to end weight is 0.111/0.5 = .222 or another way to say it is that the final weight of the hops is somewhere between 1/4 and 1/5 the starting weight.
